This invention relates to a video imagery device, especially for a television homing unit. This application is of particular interest but should not be considered as implying any limitation since the device can be incorporated for example in a target-designating system or in a video-contrast tracking system, and so on.
The design solution usually adopted for the construction of a video-imagery homing unit consists in placing the image detector and its optical system on a common support which permits of orientation along two axes, namely a pitch axis and an azimuth axis. The support thus equipped is stabilized either directly by a gyro rotor placed on the same support which is formed by a gimbal suspension or indirectly by means of a mechanical or electrical connection with a stabilized platform. Under these conditions, the optic axis constituting the line-of-sight of the device is stabilized irrespective of the relative orientation of the longitudinal axis of the missile which supports the unit as a whole. This assembly calls for electrical connections between the movable portion of the support which is constituted by a gimbal suspension and carries the detector and the portion which is constituted by the missile and provided with the supply circuits as well as the circuits for processing detected signals. Parasitic torques are consequently induced by the electrical connections and give rise to precession and drift of the gyroscope assembly.